The invention relates to knives and provides a knife which is particularly suitable for removing flashing from small plastics mouldings, as well as for other similar tasks. Flashing may be removed from plastics mouldings by inclining the blade of a knife to the surface of the moulding and running the cutting edge of the blade along the surface at an angle, either towards or away from the user, so as to strip the flashing from the moulding.
While this may be achieved with a knife having a simple exposed blade, it is desirable, particularly for industrial use, that the cutting edge of the blade should be guarded so as to prevent accidental injury to the user. A common type of safety knife for this purpose comprises a train body formed with a slot, the blade being mounted on the main body with a portion of the cutting edge of the blade extending across the slot at a location spaced inwardly from the mouth of the slot. With such a knife materials may be cut by introducing the material into the slot and pushing or pulling the knife across it so that the material is forced against the blade. Since the blade is protected within the slot the risk of injury to the user is slight.
However, there are many types of plastics mouldings, and particularly very small mouldings, where the use of such a safety knife may be inappropriate and may not allow sufficient access to the flashing in the required manner. For example, many plastics mouldings are formed with small holes where flashing projects from the inner periphery of the hole. It is not possible to remove such flushing with a safety knife of the kind described.
The present invention provides an improved form of knife where the cutting edge of the blade is protected but where the cutting edge may reach regions of a moulding which might be inaccessible to the blade of a conventional safety knife,
According to the invention there is provided a knife comprising a handle, a blade, having a cutting edge, mounted on the handle, and a guard mounted on the handle alongside the blade, the guard having an edge which is substantially parallel to, and spaced from, the cutting edge of the blade. Preferably the edge of the guard is located beyond the cutting edge and to one side of the general plane of the blade.
The guard tray comprise an elongate rod-like element extending generally parallel to at least a portion of the cuffing edge of the blade. Preferably, however, the guard comprises a plate-like element, the general plane of which is inclined at an angle to the general plane of the blade, so that the guard and blade diverge as they extend away from the cutting edge of the blade.
In a preferred embodiment the plate-like guard comprises a second blade having a cutting edge, the cutting edge of the second blade being substantially parallel to, and spaced from, the cutting edge of the first said blade.
Each blade may comprise a main part having a cutting edge, and a root part which is mounted on the handle of the knife.
Alternatively the first blade may comprise a main part having a cutting edge, and a root part which is mounted on the handle of the knife, and the second blade is mounted on the first blade. The second blade may be mounted on the first blade by means of a spacer shaped to hold the blades qt the required angle to one another.
In another arrangement the first and second blades may be both mounted on a support element which is, in turn, mounted on the handle of the knife. The support element may comprise a metal tang on opposite sides of which the blades are mounted at the required angle to one another by spacers, the metal tang having a root part which in mounted on the handle of the knife.
In any of the above arrangements where two blades are provided, the two blades may be connected together by a spacer so as form a unit.
In any of the above arrangements also the cutting edge of one of the blades may be formed with a cut-out, which may, for example, be semi-circular.
Where the guard is a plate-like element the edge of the plate-like element may be formed with a cut-out.
In any of the arrangements according to the invention at (cast one blade may be detachably mounted on the handle. For example, at least one blade may be mounted on an intermediate heart part which is detachably mounted on the handle. The head part may be formed from a material which is integrally moulded around a part of the blade or blades.
Alternatively, at least one blade may be permanently mounted on the handle. For example, the handle may be formed from a material which is integrally moulded around a part of the blade or blades.
At least one blade may be mounted on the handle so as to be retractable into the handle. The retractable blade is preferably spring-urged to an extended position where its cutting edge projects from the handle, there being connected to the blade a manipulating member by movement of which the blade can be retracted into the handle against the action of the spring. Where two blades are provided, both blades may be retractable into the handle.
The invention includes within its scope an assembly of two blades connected together by a spacer so that the cutting edge of each blade is substantially parallel to, and spaced from, the cutting edge of the other blade.